Taken daily in small doses the birth control prevent ovulation and therefore fertilization. Taken once in a larger dose, the same pill causes a hostile uterine environemnt to prevent implantation of a fertilized egg/embryo. Big difference.
Even without the pro life arguement, which I personally believe takes precedence, I am still against plan B otc. The need for plan B admits unprotected sex. Where is the counselling on STD's, how to prevent them, getting the person on a regular prevention form of birth control rather than an after the fact "emergency" contraception?
Putting aside the argument of whether or no it's an abortion, this stuff is dangerous. Even in the information Planned Parenthood puts out, they tell you flat out that it increases your risk of developing cancer in the future.
Also, does it make sense that the birth control pill isn't over-the-counter, but this pill is available?